Influence of an Apical Negative Pressure Irrigation System on Bacterial Elimination during Endodontic Therapy: A Prospective Randomized Clinical Study

Introduction: Recent in vitro studies that use an apical negative pressure irrigation system, Endo Vac, have demonstrated promising results in the production of debris-free root canals, while also preventing potential extrusion of irrigants into the periapical region. We conducted a randomized, controlled, prospective clinical study to determine whether the use of Endo Vac irrigation (Endo Vac group) was more efficient compared with standard needle irrigation (control group) in obtaining canals from which microbes could not be cultivated. Methods: Routine endodontic therapy was performed in 48 patients with necrotic, single-rooted, single-canal teeth. The patients were randomly assigned to either the Endo Vac group (n = 25) or control group (n = 23). Irrigation with either method was carried out with 0.5% sodium hypochlorite. After surface disinfection, before instrumentation and on completion of chemomechanical preparation, intracanal microbial samples were obtained and cultured under anaerobic conditions. The frequency of microbial cultivability by using either irrigation system was analyzed. Results: The frequency of obtaining culture-negative root canals was 90.9% and 82.6% for the control group and Endo Vac group, respectively. There was no significant difference in the antimicrobial efficacy of either control group or Endo Vac group (Fisher exact test, P = .665). Furthermore, no significant association between study variables and the irrigation systems' antimicrobial efficacy was found (P > .05). Conclusions: The results of this prospective in vivo study demonstrate that the antimicrobial efficacy of EndoVac irrigation is comparable to that of standard irrigation. (J Endod 2012;38:1177-1181)